I've heard from others and looked into it a bit myself, but it's looking like you can't actually do anything right now. You can, however, add crysta to your account via the square enix account management (not just the FFXIV one) and I'm 99.999% sure they are drawn from the same account. I'm not sure why they have not implemented the payment system yet, as the 1.0 people were supposed to have their time up in just over a week (but that has now changed), but I'm sure it will be soon.